A typical multi-cavity hot runner injection molding apparatus includes a heated manifold for delivering a pressurized melt stream to a plurality of heated nozzles. Each heated nozzle delivers melt to a respective mold cavity through a mold gate. Cooling channels are provided adjacent to the mold cavities to cool the molded parts prior to ejection from the injection molding apparatus.
The manifold and nozzles are typically heated by heaters that are linked to a power source through electrical wiring. In many cases, each nozzle includes both a heater wire and a thermocouple wire. As such, the routing of wiring throughout the hot runner may be difficult, particularly in systems with a large number of nozzles and, consequently, a large volume of wires. One technique for routing wiring includes machining wire-receiving grooves into mold plates surrounding the hot runner in order to direct the wires through the hot runner mold to the outside in order to connect to a remote power source. This solution is time consuming because the layout of the wire-receiving grooves often needs to be custom-designed for each injection molding application.
The routing of hydraulic fluid and/or compressed air conduits to actuators within a valve-gated injection molding apparatus also presents a challenge. Conventionally, conduits are either machined in the mold or via external tubing, and are coupled to a hydraulic fluid and/or compressed air source to control the valve pin actuators.
Routing of wiring and hydraulic fluid/compressed air conduits is a time consuming labor intensive process and the volume of the lines in the mold can become quite large and awkward to handle.
Hot runner molds with large volumes of wires and fluid lines can be difficult to disassemble should maintenance on the hot runner be required.
There is therefore a need to simplify the routing process.